H1N1 Vaccination FAQs

FAQs Overview

What is the H1N1 vaccine for?

Though the new strain of Influenza A (H1N1) is known to be contagious, most people who were infected recover with rest and symptomatic treatment. Getting the vaccination is an effective way to build up your immunity and protect yourself against the H1N1 virus.

Who is likely to be benefit from the H1N1 vaccine?

  • Elderly patients
  • Frequent travellers
  • People with chronic medical conditions (lung disorders, heart diseases, diabetes, kidney failure, neuromuscular disorders); and
  • People with chronically suppressed immunity due to disease or long-term medication.

Who should not get the vaccine or should wait to receive one?

Please inform the doctor if you had a severe allergic reaction previously after a dose of seasonal influenza vaccine, or are allergic to high protein food (like egg or chicken protein). The doctor will be able to advise if you should get vaccinated.

You should have fully recovered from moderate or severe illnesses before receiving the vaccine.

Before vaccination, you should inform your doctor if you:

  • Have a fever or an infection (You should postpone getting your vaccination if you are running a fever or feeling unwell);
  • Was vaccinated (i.e. seasonal flu vaccine or any other vaccines) recently (Please note that you need at least one week before getting the next vaccination);
  • Have been infected by H1N1 influenza virus before;
  • Are allergic to any medications or vaccines, or food (e.g. high protein food such as egg or chicken);
  • Have other illnesses;
  • Are taking other medicines and/or
  • Are pregnant.

Will I get immediate immunity after vaccination? How long will I be protected for?

Immunity after vaccination varies from person to person, but you will generally start producing the antibodies that provide protection after two weeks. It will protect the majority of people for at least 6 months to a year. It is important to remember that no vaccine provides 100% protection in every person vaccinated.

This vaccine only protects you against the H1N1 2009 influenza virus. You can still be infected by other seasonal influenza viruses.

What are the common side effects?

The common side effects include pain at the site of the injection, fever, headache, muscle aches and pains. These side effects will usually resolve in a few days.

When do I know that a side effect is serious and I need to consult a doctor?

Please see a doctor if you experience any of the following:

  • The side effects persist for more than a few days;
  • Your fever is high (>38 degrees Celsius) or persists for more than 48 hours (2 days) despite taking paracetamol.
  • You have fever accompanied by fits.
  • You experience severe allergic reactions where you may feel severe anxiety, itchy skin rash, swelling of the lips and face or difficulty in breathing.

Does a patient who was previously a confirmed case of Influenza A/H1N1 need to take this vaccination?

There is no need for a confirmed case of Influenza A/H1N1 infection to be vaccinated with the H1N1 vaccine.

Can a patient take the flu vaccination and H1N1 vaccination?

Currently, there are no documented complications if a patient decides to be vaccinated with both the seasonal flu and H1N1 vaccines. However, MOH recommends H1N1 and seasonal influenza vaccine to be given one week apart as a precaution in case of overlapping side effects. As H1N1 is a new vaccine, MOH is regularly reviewing the safety and efficacy test results.

Is the seasonal flu vaccination still effective?

Seasonal influenza vaccination is still recommended for the general public. Even though its does not protect against H1N1 infection, it protects one against the seasonal influenza infection that is associated with significant mortality (there are about 600 seasonal influenza related death in Singapore in 2008).